JP2011168111A - Compound solid tire - Google Patents

Abstract

A composite solid tire comprising an inner layer made of a rubber material and an outer layer made of a polyurethane elastomer material, wherein the bonding strength of the two layers is effectively enhanced, and the composite solid tire has excellent durability. To provide.
An anchor portion is formed by integrally forming a circumferential groove 22 and 22 having a predetermined depth on an outer peripheral surface 16 of an inner layer 14 made of a rubber material and made of the same polyurethane elastomer material as an outer layer 18. The outer solid layer 18 is integrally formed on the outer circumferential surface of the inner layer 14 so that the outer circumferential layers 24 and 24 are positioned so as to fill the circumferential grooves of the circumferential grooves 22 and 22, thereby forming the composite solid tire 10. did.
[Selection] Figure 2

Description

  The present invention relates to a composite solid tire, and more particularly to a composite solid tire including an inner layer made of a rubber material and an outer layer made of a polyurethane elastomer material.

  Conventionally, an air having a structure in which air is enclosed in a hollow portion as a tire that bears a load on a vehicle such as an automobile or an industrial vehicle and has a function of transmitting a smooth force between the vehicle and a road surface. A solid tire made of a solid rubber ring is well known in addition to a tire. The solid tire uses load capacity, shock absorbing capacity, and rubber elasticity as tire functions, and is mainly used for low speed, heavy load vehicles such as forklift trucks, industrial tractors, battery storage vehicles, trailers, etc. In many cases, a single tread rubber is baked directly on the wheel, a rubber material is vulcanized and bonded to the base band, and the ring is pressed into the wheel. Such a tread rubber is fitted into the outer periphery of the wheel.

  By the way, such a solid tire is generally used as a solid rubber tire in which a tread rubber is composed of a rubber material such as NR or SBR. However, such a tire is in contact with a road surface and has a frictional force. Since the vehicle is allowed to move by the long-term use, the wear of the contact surface with the road surface will progress and the service life will be discarded. Has become a major social problem. In particular, solid rubber tires are heavier than pneumatic tires used in passenger cars, etc., making them difficult to handle, difficult to incinerate, and difficult to use for other purposes. There is a great difficulty in its disposal.

  Therefore, the present inventor previously described the circumference of a worn solid rubber tire in which a predetermined rubber layer is left in Japanese Patent Application Laid-Open No. 2004-359219 (Patent Document 1) and Japanese Patent No. 4391274 (Patent Document 2). The structure of a composite solid tire was clarified by covering a surface with a polyurethane elastomer layer having a predetermined thickness. According to the composite solid tire having such a configuration, the annular tread portion attached to the outer peripheral portion of the wheel includes an annular rubber layer having a predetermined thickness that forms the inner layer portion of the solid tire, Therefore, the impact received from the ground contact surface of such a tread portion can be effectively absorbed and relaxed by the inner rubber layer. At the same time, the outer polyurethane elastomer layer that provides the contact surface of such a tread is significantly enhanced in durability by the good wear resistance characteristic of the polyurethane elastomer material. The service life can be remarkably improved.

  However, even in the composite solid tire whose service life has been improved in this way, the rubber layer on the inner peripheral side and the polyurethane elastomer layer on the outer peripheral side can be used under a certain condition under a long period of use. It was newly confirmed that there is a possibility that the polyurethane elastomer layer may be peeled off due to the unbonding. For example, in a forklift truck in which such a composite solid tire is suitably employed, a large balance weight is generally attached to the rear wheel side steered by a steering operation. A large load is applied. For this reason, when an operation is performed in which the tread surface of the tire is twisted with respect to the road surface by a steering operation, a large stress is applied to the tire in the thrust direction (axial direction), and such a force is applied over a long period of time. By repeatedly acting, the rubber layer and the polyurethane elastomer layer may be disconnected (adhered).

  In addition, various compounding agents such as plasticizers, softeners, anti-aging agents and the like mixed in the rubber material of the raw material from the rubber layer on the inner circumference side while such a composite solid tire has been used for a long time. When it comes out from the bleed, it may worsen the action of the adhesive that bonds the rubber layer and polyurethane elastomer layer, and it is also caused by friction between the tire and the road surface during use. The running heat may also reduce the effect of such an adhesive. As a result, the rubber layer and the polyurethane elastomer layer are bonded to each other by the lateral (axial) force applied to the tire. It becomes easy to peel off from the surface, and the durability of the tire is lowered.

JP 2004-359219 A Japanese Patent No. 4391274

  Here, the present invention has been made in the background of such circumstances, and the problem to be solved is a composite solid composed of an inner layer made of a rubber material and an outer layer made of a polyurethane elastomer material. An object of the present invention is to provide a composite solid tire that effectively enhances the bonding strength of these two layers and is more durable.

  In the present invention, in order to solve such a problem, an inner layer made of a rubber material and having a predetermined thickness, and an outer layer integrally formed of a polyurethane elastomer material on the outer peripheral surface of the inner layer. The same polyurethane elastomer material as that of the outer layer, the composite solid tire having at least one circumferential groove formed on the outer circumferential surface of the inner layer and positioned so as to fill the circumferential groove The gist of the present invention is a composite solid tire characterized in that an anchor portion made of is integrally formed on the outer layer.

  According to one desirable aspect of the composite solid tire according to the present invention, a plurality of connection pins made of polyurethane elastomer material are provided on the outer peripheral surface of the inner layer at a predetermined distance in the circumferential direction. At the same time, the tip side portions of the connection pins are embedded in the outer layer, and the outer layer and the inner layer are connected by the connection pins.

  In another preferred embodiment of the composite solid tire according to the present invention, the two strips of the circumferential groove extend in parallel to each other in the circumferential direction on the outer circumferential surface of the inner layer. At the same time, the plurality of connection pins are disposed in the circumferential direction at the outer peripheral surface portion of the inner layer between the circumferential grooves.

  Furthermore, according to another desirable aspect of such a composite solid tire according to the present invention, the connection pin has a cross-sectional diameter corresponding to 10 to 30 mmφ, and the inner layer and the outer layer In addition, each of the circumferential grooves has a length of 10 to 30 mm, and according to another preferred embodiment, the circumferential groove has a rectangular cross-sectional shape.

  Furthermore, in the composite solid tire according to the present invention, advantageously, a rubber layer having a predetermined thickness given by the residual wear in a worn solid rubber tire is used as the inner layer.

  As described above, according to the composite solid tire having the structure according to the present invention, the anchor portion made of the polyurethane elastomer material formed integrally with the outer layer is formed on the outer peripheral surface of the rubber inner layer. From the place where it is provided so as to fill the inside, in other words, from the place where the anchor part integrally formed with the outer layer is fitted in the circumferential groove of a predetermined depth provided in the inner layer, the tire In addition to the bonding force between the outer peripheral surface of the inner layer and the inner peripheral surface of the outer layer, the load applied in the thrust direction (axial direction) of the Since it is received by contact, the stress applied to the joint portion is effectively dispersed, and therefore, the possibility that the inner layer and the outer layer are peeled off can be advantageously reduced or eliminated. Because . As described above, the inner layer and the outer layer of the composite solid tire can be more firmly joined, and thereby the durability of the composite solid tire can be further effectively improved.

  Further, according to one of the desirable embodiments of the present invention, according to the composite solid tire having a structure in which a plurality of connection pins are embedded in a plurality of locations in the circumferential direction, the inner layer and the outer layer have the above-described circumference. In addition to the connecting structure between the groove and the anchor portion, it is connected by a plurality of connecting pins made of polyurethane elastomer material embedded between the two layers, so that the inner side due to the load applied in the axial direction of the tire The stress applied to the connecting portion between the layer and the outer layer can be more effectively distributed and received. As a result, the inner layer and the outer layer can be further firmly joined to each other to form a composite solid tire having higher durability.

It is side explanatory drawing which shows an example of the composite solid tire according to this invention. FIG. 2 is a cross-sectional explanatory view showing a radial cross-sectional view taken along the line AA in FIG. 1. FIG. 3 is a partial cross-sectional explanatory diagram showing an enlarged B portion in FIG. 2. It is explanatory drawing of the cross section equivalent to FIG. 2 which shows another example of the composite solid tire according to this invention. FIG. 5 is a cross-sectional explanatory view showing a CC cross section in FIG. 4.

  Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

  First, FIG. 1 shows an embodiment of a composite solid tire structured according to the present invention in the form of a side view. Here, the composite solid tire 10 exhibits a donut shape as a whole, and a wheel 12 is attached to the inner peripheral portion of the donut shape, while a predetermined thickness is set so as to be positioned on the inner peripheral side of the donut shape. An inner layer 14 made of a rubber material is provided. An outer layer 18 made of a polyurethane elastomer material is integrally formed with a predetermined thickness on the outer peripheral surface 16 of the inner layer 14 to form a tread surface 20. That is, the composite solid tire 10 has a two-layer structure including the inner layer 14 and the outer layer 18 each having a predetermined thickness.

  More specifically, the inner layer 14 uses a rubber material such as NR, IR, SBR, BR, EPM, EPDM, IIR, and blends one or more of them, as in the conventional solid rubber tire. Generally, it is formed by vulcanization molding into an annular shape (doughnut shape) using a blend rubber mainly composed of NR and IR. On the outer peripheral surface 16 of the inner layer 14, as shown in the cross-sectional view of FIG. 2, a plurality of circumferential grooves having a predetermined depth, here, two circumferential grooves 22, 22 are formed on the outer circumferential surface 16. Are formed so as to extend in parallel to each other and in the circumferential direction with a predetermined interval in the width direction. Further, as shown in FIGS. 2 and 3, the circumferential groove 22 has a rectangular cross-sectional shape, and generally has a groove width of about 10 to 30 mm and a groove depth of about 10 to 30 mm. In, it is formed.

  On the other hand, the outer layer 18 is casted on the outer peripheral surface of the inner layer 14 by using a conventionally well-known polyurethane elastomer material, thereby giving the outer diameter of the target composite solid tire 10. In thickness, it is integrally formed on the outer peripheral surface of the inner layer 14. Furthermore, anchor portions 24 and 24 having shapes corresponding to the circumferential grooves 22 and 22 formed on the outer peripheral surface 16 of the inner layer 14 are provided in the circumferential direction at the interface portion between the outer layer 18 and the inner layer 14. Two protrusions extending continuously in parallel with each other are integrally formed of the same polyurethane elastomer material as that of the outer layer 18.

  The anchor portions 24, 24 of the outer layer 18 are formed so as to fill the grooves of the peripheral grooves 22, 22 of the inner layer 14, that is, formed on the outer peripheral surface 16 of the inner layer 14. In the form in which the anchor portion 24 provided so as to protrude from the inner peripheral surface of the outer layer 18 is fitted in the groove of the peripheral groove 22 formed, the inner layer 14 and the outer layer 18 are integrated, and the whole It is formed as a composite solid tire 10 having an annular shape (doughnut shape).

  The integration of the inner layer 14 and the outer layer 18 is performed by appropriately selecting various known methods, for example, applying an adhesive to the two joint surfaces and bonding them. . In addition, the composite solid tire 10 is attached to the wheel 12 such that the outer peripheral surface of the wheel 12 attached to the axle of the vehicle is well known with respect to the inner peripheral portion of the donut, that is, the inner peripheral portion of the inner layer 14. As shown, it can be attached in a method such as a printing type, a press-fitting type, or a fitting type.

  By the way, as the polyurethane elastomer material forming the outer layer 18 in the composite solid tire 10, various known materials such as a thermosetting material and a room temperature curing material are appropriately selected and adopted. It becomes. Here, for example, a room temperature curing type polyurethane raw material generally uses an MDI-based isocyanate such as modified diphenylmethane-4,4′-diisocyanate as a polyisocyanate component, and uses a polyether polyol or the like as a polyol component. And, as a catalyst for rapidly reacting and curing the polyisocyanate component and the polyol component at low temperature, an aromatic amine such as an aromatic primary amine is used. For example, it can be reaction-cured at a temperature of 10 to 50 ° C. using a product marketed under the name “Baytec” from Bayer AG, Germany. In addition, after about 1 minute has passed after the mixing of the respective components, the reaction has achieved a certain degree of solidification, and after about 3 days at room temperature, the substantial reaction has been completed and the final physical properties have been reached. Will be realized.

  Further, in the composite solid tire 10 constituted by the outer layer 18 of the polyurethane elastomer material as described above, the corners on both sides in the width direction of the tread surface 20 have predetermined curvatures as shown in FIG. The curved portions 26 and 26 having a radius are formed. Note that, when the composite solid tire 10 is attached to the vehicle, such a curved portion 26 has a curvature radius of the curved portion 26 formed on the corner on the outer side of the vehicle so that the corner on the other side is the same. It is preferable that the radius of curvature is larger than the radius of curvature of the curved portion 26 formed in the portion. By doing in this way, the effect of stress concentration on the corner of the tread surface 20 (corner of the outer layer 18) located on the outer side of the tread surface 20 in contact with the road surface, which is likely to be subjected to a large stress when the vehicle is traveling, is effective. Therefore, the fear that the corners of the outer layer 18 may be lost can be advantageously avoided or suppressed.

  Thus, according to the composite solid tire 10 configured according to the present invention, the anchor portion 24 formed integrally with the outer layer 18 is fitted into the groove of the groove portion 22 formed on the outer peripheral surface of the inner layer 14. Therefore, in addition to the joint between the outer peripheral surface of the inner layer and the inner peripheral surface of the outer layer with respect to the load applied in the thrust direction (axial direction) of the tire, the anchor portion 24 and the peripheral groove 22 It is possible to counteract by fitting between the two. As a result, since the connection between the inner layer 14 and the outer layer 18 can be realized more firmly, the possibility that the outer layer 18 may be detached from the inner layer 14 can be advantageously reduced. As a result, the durability of the composite solid tire can be more effectively enhanced.

  Of course, the composite solid tire 10 is composed of an inner layer 14 made of a rubber material having a predetermined thickness and an outer layer 18 made of a polyurethane elastomer material integrally formed thereon. The impact received from the ground is effectively absorbed and alleviated by the inner layer 14, and the cushioning or shock-absorbing property against the impact can be advantageously expressed, and the outer layer 18 serving as the grounding surface has a good property of the polyurethane elastomer material. Since the durability is remarkably enhanced by the excellent wear resistance characteristics, the characteristic that the useful life of the composite solid tire 10 can be advantageously improved is exhibited.

  In addition, unlike the rubber inner layer 14, the outer layer 18 made of such a polyurethane elastomer material is not compounded with carbon black as a reinforcing agent. Even if the tire 10 is rolled, there is no black tire mark, so that it contributes to beautification of the environment and does not cause any fear of deteriorating the working environment.

  The composite solid tire 10 having the configuration according to the present invention as described above can be manufactured by using various known methods. For example, in Patent Document 1 (Japanese Patent Laid-Open No. 2004-359219) described above. It can be produced using a casting method as has been clarified. Then, when manufacturing the composite solid tire 10 by such a casting method, a predetermined number of circumferential grooves 22 are formed on the outer peripheral surface of the annular rubber member that provides the inner layer 14, In the casting apparatus, the inner layer is set by setting the outer layer 18 in the outer mold and filling the gap between the outer peripheral surface of the rubber member and the inner peripheral surface of the outer mold with a predetermined polyurethane elastomer material. The anchor portion 24 adapted to fill the 14 circumferential grooves 22 can be formed integrally with the outer layer 18.

  In the present invention, in addition to the above-described embodiment, a composite solid tire having a configuration as shown in FIGS. 4 and 5 is further advantageously employed. There, as in the composite solid tire 10 described above, two circumferential grooves 22 formed on the outer circumferential surface 16 of the inner layer 14 so as to extend in parallel to the circumferential direction at a predetermined interval from each other. , 22 are formed. A plurality of (in this case, six) connection pins 28 formed of a predetermined polyurethane elastomer material are disposed at predetermined intervals in the circumferential direction (here, a portion between the peripheral grooves 22 and 22). And one end of the connection pin 28 is embedded in the inner layer 14 at a predetermined depth.

  Specifically, the connection pin 28 is erected such that the other end protrudes from the outer peripheral surface 16 of the inner layer 14 by a predetermined height, and the inner layer of the connection pin 28 is provided. The protruding portion from 14 is configured to be embedded in the outer layer 18. That is, a plurality of connection pins 28 having a predetermined length are disposed so as to be embedded between the outer layer 18 and the inner layer 14, so that the two layers are connected to the plurality of connection pins 28. It is comprised so that it may be in the state connected by.

  As the polyurethane elastomer material for forming such a connection pin 28, various known materials can be appropriately selected and used. Of these, the same material as that for forming the outer layer 18 is used. Is preferably employed. That is, by forming the outer layer 18 and the connection pin 28 from the same polyurethane elastomer material, it is possible to improve the connectivity thereof, and in addition, the outer layer 18 is cast-molded. The advantage that the connection pin 28 can be formed at a low cost by using the end material generated when forming with the use of is also obtained.

  In addition, the connection pin 28 may be of various shapes such as a prismatic shape or a cylindrical shape, but is preferably a cylindrical shape having a cross-sectional diameter corresponding to 10 to 30 mmφ. It will be. Moreover, it is preferable that the embedding (penetration) depth of the connection pin 28 into the inner layer 14 and the outer layer 18 is about 10 to 30 mm, respectively.

  Furthermore, in the composite solid tire 30 exemplified here, the six connection pins 28 are arranged at regular intervals in the circumferential direction. However, the number is 5 or less, or 7 or more. Of course, it is also possible to arrange them in the number. However, in consideration of an increase in bonding strength due to the required connection pins 28, costs at the time of manufacturing, etc., it is preferable that the number is about 4 to 8.

  According to the composite solid tire 30 having such a configuration, in addition to the fitting between the circumferential groove 22 provided in the inner layer 14 and the anchor portion 24 provided in the outer layer 18, the connection pin 28 is further provided. As a result, the inner layer 14 and the outer layer 18 are connected and integrated, whereby the bonding strength between the inner layer 14 and the outer layer 18 can be more effectively increased. In other words, the load applied in the axial direction (lateral direction) of the tire is received by the bonding force between the inner layer 14 and the outer layer 18 and the contact between the side surface of the anchor portion 24 and the side wall surface of the circumferential groove 22. In addition, both ends thereof are supported by connection pins 28 embedded in the inner layer 14 and the outer layer 18, respectively, thereby more effectively distributing the stress applied to the joint portion of the two layers. It becomes possible. As a result, it is possible to provide a composite solid tire 30 that advantageously reduces the risk of the outer layer 18 coming off from the inner layer 14 and thus exhibits even higher durability.

  Although preferred embodiments of the present invention have been described in detail above, they are literal examples, and it is understood that the present invention is not construed as being limited in any way by the description of such embodiments. It should be.

  For example, in the above-described embodiment, the number of the circumferential grooves 22 formed on the outer peripheral surface 16 of the inner layer 14 is two. However, it is sufficient that at least one circumferential groove 22 is formed, or 3 It is also possible to form a circumferential groove 22 that is more than a strip. In accordance with the number of the circumferential grooves 22, the anchor portions 24 formed integrally with the outer layer 18 are formed in the corresponding positions by the corresponding number, and the circumferences of the respective circumferential grooves 22 are formed. The anchor portion 24 formed at the corresponding position is filled in the groove, so that a composite solid tire is formed.

  Further, in any of the above-described embodiments, the circumferential groove 22 formed on the outer circumferential surface 16 of the inner layer 14 has a rectangular cross-sectional shape, but it has a dovetail shape, a trapezoidal shape, and many other shapes. A circumferential groove 22 having a cross-sectional shape such as a square shape may be used.

  In addition, as the inner layer 14 of the exemplified composite solid tires 10 and 30, a tread surface of what is generally marketed as a solid rubber tire is used in addition to a newly created one made of a predetermined rubber material. The peripheral groove 22 is obtained by using a material that is worn down by wear and remains at a required thickness over the entire circumference of the wheel 12 and that is subjected to a known cutting process or the like on its outer peripheral surface (tread surface). It is also possible to have formed. As described above, the rubber layer that remains after the worn solid rubber tire is reused as the inner layer to form the composite solid tire 10 (30), thereby effectively reducing the production cost of the composite solid tire. As a result, it is possible to advantageously reduce the cost increase and the adverse environmental impact caused by the disposal of the worn solid rubber tire.

  In addition, although not enumerated one by one, the present invention can be carried out in a mode to which various variations, modifications, improvements, and the like are added based on the knowledge of those skilled in the art. It should be understood that all belong to the scope of the present invention without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 10 Composite solid tire 12 Wheel 14 Inner layer 16 Outer surface 18 Outer layer 20 Tread surface 22 Circumferential groove 24 Anchor part 26 Curved part 28 Connection pin

Claims (6)

A composite solid tire comprising an inner layer of a predetermined thickness made of a rubber material and an outer layer integrally formed of a polyurethane elastomer material on the outer peripheral surface of the inner layer,
An anchor portion made of the same polyurethane elastomer material as the outer layer and having at least one circumferential groove formed on the outer peripheral surface of the inner layer and positioned so as to fill the inner groove is formed on the outer layer. A composite solid tire characterized by being integrally formed with.   On the outer peripheral surface of the inner layer, a plurality of connection pins made of a polyurethane elastomer material are erected at a predetermined distance in the circumferential direction, and the tip side portions of the connection pins are embedded in the outer layer. The composite solid tire according to claim 1, wherein the outer layer and the inner layer are connected to each other by the connection pins.   Two strips of the circumferential groove are formed on the outer circumferential surface of the inner layer so as to extend in parallel to each other in the circumferential direction, and the plurality of connection pins are disposed on the inner layer outer circumferential surface portion between the circumferential grooves. The composite solid tire according to claim 2, wherein the tire is disposed in a circumferential direction.   The connection pin has a cross-sectional diameter corresponding to 10 to 30 mmφ, and protrudes into the inner layer and the outer layer in a length of 10 to 30 mm, respectively. The composite solid tire described in 1.   The composite solid tire according to any one of claims 1 to 4, wherein the circumferential groove has a rectangular cross-sectional shape. The composite solid tire according to any one of claims 1 to 5, wherein the inner layer is a rubber layer having a predetermined thickness that is given as a residual wear in a worn solid rubber tire.

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